JP2021523287A - Phase change barrier and how to use it - Google Patents

Abstract

Modified surfaces and methods of use thereof are provided to prevent or delay the occurrence of phase changes such as condensation or frost formation. The present invention is limited to energy barriers to nucleation phase changes such as, but not limited to, condensation and crystallization, or surfaces that increase the propulsive force required for nucleation phase changes, as well as anti-fog glass applications and sensible heat cooling. With respect to its use, such as prevention of condensation on heat exchangers in systems that require.
[Selection diagram] Fig. 2

Description

Cross-reference of related applications
[01] This application claims the interests of US Provisional Application No. 62 / 669,507 filed May 10, 2018, which is incorporated herein by reference in its entirety.

[02] The present invention is an energy barrier against nucleation phase changes such as, but not limited to, condensation and crystallization, or surfaces that increase the propulsive force required for nucleation phase changes, as well as anti-fog glass applications and sensible heat. It relates to its use, such as prevention of condensation on a heat exchanger, in a system that requires only sensible cooling.

[03] Typical condensation on low-energy surfaces does not produce round droplets during nucleation, but rather water and other condensates condense at a stressed, lower contact angle. Differences in contact area in nucleation through the wet state as compared to the dewetting state can shift the energy barrier of droplet formation (ie, modify the energy barrier of the condensation process). A typical surface condenses water in the air at the dew point. Condensation is often undesirable on surfaces where electronic devices such as computers or data centers that utilize sub-ambient cooling are located, or on glass surfaces where visibility is desired, such as windows, lenses, and mirrors.

[04] The solution to prevent condensate from the heat transfer surface usually needs to keep the coolant temperature significantly above the dew point, which leads to a decrease in heat transfer capacity and limits the working range. there is a possibility. In many cases, the coolant temperature is lowered to the minimum amount allowed by system control to prevent condensation while keeping the volume as high as possible. In the event of control or input errors to the system, there is a risk of water condensing on the surface and potentially destroying the electronics. A solution is needed to allow the lowest possible coolant temperature to maximize heat transfer, while allowing the maximum difference between the coolant temperature and the effective generation of condensation. Currently, the occurrence of this condensation is the dew point.

[05] Condensation and fogging of glass windows and mirrors such as shower mirrors, automotive glass, and building windows are also a problem. A typical solution is now to wipe the condensate with a towel or squeegee, or use a hydrophilic coating to diffuse the condensate into a thin film that is still visible through the window or in the mirror. It is to make the reflected image visible. These hydrophilic coatings are problematic in that they accelerate condensation and deposit contaminants on the surface, resulting in increased cleaning frequency.

[06] According to classical nucleation theory, the free energy of uniform nucleation is the sum of the volume term and the surface term, ΔG _homo = 4/3 (πr ³ ) Δg + 4πr ² σ [in the equation, r is the formation phase. The radius of the sphere, Δg is the difference between the free energy per unit volume of the hypersaturated phase and the free energy of the nucleation phase, and σ is the surface tension of the interface between the nucleus and its surroundings]. ^{The critical radius r *} of the formation with the free energy barrier of ΔG _homo ^* can be calculated by taking d (ΔG _homo ) / dr = 0. The radius at which this derivative becomes zero ^{corresponds to r *} = -2σ / Δg. Then, the free energy of uniform nucleation can be defined as _{ΔG homo} ^* = ΔG _homo (r ^* ) = 16πσ ³ / (3 ( ^{Δg) 2).} Heterogeneous nucleation has a lower energy barrier that can be determined as a function of the contact angle (θ) on the surface for the vapor-to-liquid phase change. This relationship _{can be approximated as ΔG hetero} ^* = f (θ) ΔG _homo ^* [in the equation, f (θ) = (2-3 cos ^{θ + cos 3} θ) / 4].

[07] Heat exchangers for refrigerators or freezers of various sizes, from small dormitory room units to industrial-scale distribution center units, on the surface in many applications, as well as the vapor-to-liquid transition. For example, it is desirable to increase the barrier of phase transition from liquid to solid. Ice is a problem for these heat transfer systems because it requires regular shutdowns of the system to defrost, which reduces throughput and consumes large amounts of energy in industrial applications. In addition, large-scale defrosting equipment units are expensive.

[08] Accretion is also a problem on the surface of wings such as aircraft wings and wind turbines. Ice on the wing of an aircraft is dangerous for flight and must be removed before takeoff, resulting in costly delays. Wind turbines can accumulate ice, which causes a significant reduction in output power and poses a safety risk of blowing ice off the blade surface.

[09] Reduce (eg, prevent or delay) condensation of gas (eg, vapor) phases below the gas-liquid transition temperature (eg, dew point), or reduce (eg, prevent) solidification (eg, freeze) of the liquid phase. A method of (or delaying), and a system, device, and composition for carrying out the method, or a system, device, and composition in which the method is performed are provided herein.

[10] In one aspect, methods for preventing or delaying the occurrence of phase changes on the surface are provided herein. The method provides an energy barrier against a phase change from the first phase to the second phase, or a modified surface that increases the propulsion required for the phase change compared to the unmodified surface, and the fluid. The phase change is prevented or delayed as compared to the unmodified surface, comprising contacting the stream with the modified surface under environmental conditions where phase change can occur on the unmodified surface. In one embodiment, a method for preventing or delaying the occurrence of a phase change is a step of providing a modified surface that includes surface modification, except that the modified surface does not contain surface modification. An energy barrier against a phase change from the first phase to the second phase, or the driving force required for a phase change, for a substance in contact with the modified surface compared to an unmodified surface that is identical to the quality surface. A fluid stream containing a step and a substance of at least one first phase (eg, a gas (eg, steam) phase and / or a liquid phase) to a second phase on an unmodified surface. It involves contacting the modified surface under environmental conditions where phase changes (eg, gas to liquid; liquid to solid; gas to solid) can occur, and is the second on the modified surface compared to the unmodified surface. The phase change from the first phase to the second phase is prevented or delayed.

[11] In some embodiments, at least one first phase comprises a gas (eg, vapor) phase, the second phase comprises a liquid phase, and prevention or delay of phase change is on the surface. Includes prevention or delay of condensation of gases (eg, vapors) forming liquids. In one embodiment, the gas phase is water vapor, the fluid flow is air, and prevention or delay of phase change includes prevention or delay of condensation of water vapor on the surface.

[12] In some embodiments, at least one first phase comprises a gas (eg, steam) phase, the second phase comprises a solid phase, and the gas (eg, steam) is condensed on the surface. Forming a liquid (eg, condensate) and preventing or delaying a phase change includes preventing or delaying the solidification of the solid-forming liquid (eg, condensate) on the surface. In one embodiment, the gas phase is water vapor, the fluid flow is air, the liquid phase is a water condensate, and the prevention or delay of phase change is water condensation that forms water frost or ice on the surface. Includes prevention or delay of solidification of objects.

[13] In some embodiments, at least one first phase comprises a gas (eg, steam) phase and a liquid phase, the second phase comprises a liquid phase, and the prevention or delay of phase change is a surface. Includes prevention or delay of condensation of the liquid-forming gas (eg, steam) above. In one embodiment, the gas phase is water vapor, the liquid phase is liquid water, the fluid flow is air, and prevention or delay of phase change includes prevention or delay of condensation of water vapor on the surface.

[14] In some embodiments, at least one first phase comprises a gas (eg, steam) phase and a liquid phase, the second phase comprises a solid phase, and the surface is from a gas (eg, steam). Containing condensates and / or liquids of substances, prevention or delay of phase change includes prevention or delay of solidification of said condensates and / or liquids forming a solid on the surface. In one embodiment, the gaseous phase is water vapor, the liquid phase and liquid on the surface is water, the fluid flow is air, the surface contains water vapor and / or a condensate of liquid water, preventing phase change or Delays include prevention or delay of coagulation of water condensates and / or liquid water on the surface forming water frost or ice on the surface.

[15] In some embodiments, at least one first phase comprises a gaseous (eg, vapor) phase, the second phase comprises a solid phase, and prevention or delay of phase change is on the surface. Includes prevention or delay of solidification of gases (eg, vapors) forming solids. In one embodiment, the gaseous phase is water vapor, the solid is water frost or ice, and prevention or delay of phase change includes prevention or delay of solidification of water vapor forming water frost or ice on the surface. .. In one embodiment, the gaseous phase is a CO ₂ gas or a CO ₂ gas, the solid is frozen CO ₂ (CO ₂ dry ice), and the prevention or delay of phase change is CO _{2 on the surface.} Includes prevention or delay of solidification of _{CO 2} gas forming dry ice.

[16] In some embodiments, the modified surface is from a first phase to a second phase (eg, gas (eg, steam) to liquid; gas (eg, steam) to solid; liquid to solid. Subcooled below the equilibrium phase transition value (eg, temperature), the material is still present as the first phase. In various embodiments, the modified surface is at about 0.25, 0.5, 1, 2, 3, 5, or 10 ° C. than the equilibrium phase transition value from the first phase to the second phase. Subcooled to temperatures below or above, the material still exists as the first phase.

[17] In various embodiments, the energy barrier to the phase change from the first phase to the second phase is any of about 50, 60, 70, 80, 90, 95, or 99% of the uniform nucleation energy. Greater than

[18] In some embodiments, the phase change from the first phase to the second phase involves nucleation of the material on the modified surface. The modified surface or surface coating on which nucleation occurs may be, for example, a barrier coating, a conversion coating, or a combination thereof. In some embodiments, the modified surface or surface coating on which nucleation occurs is nanostructured. In some embodiments, the modified surface or surface coating on which nucleation occurs contains a metal oxide, eg, a metal oxide layer created by deposition or conversion, or a polymer, eg, an alkyl or fluoroalkyl monomer unit. Contains the polymer to be used. In some embodiments, the modified surface or surface coating comprises a terminal alkyl or fluorinated compound (s).

[19] In some embodiments, the first phase comprises predominantly water vapor and the second phase comprises liquid water or water ice. In some embodiments, the first phase is air containing water vapor and the second phase is liquid water or water ice. In some embodiments, the first phase is liquid water and the second phase is water ice. In some embodiments, the first phase contains carbon dioxide vapor and the second phase is dry ice or solid CO ₂ .

[20] In some embodiments, the first phase comprises gaseous vapors and the second phase comprises clathrate compounds. For example, the material may be raw natural gas, the first phase comprising a gas (eg vapor) phase and the second phase comprising clathrate compounds. In one embodiment, the first phase is a gas (eg, vapor) or liquid and the second phase is a supercritical phase.

[21] In some embodiments, the material is a metal, the first phase contains metal vapor and the second phase contains condensed metal vapor.
[22] In some embodiments, condensed droplets of fluid above the critical radius of formation are present in a dewetting Cassie-Baxter state. In some embodiments, condensed droplets of fluid above the critical radius of formation, which previously existed in the wet Wenzel state, are present in the dewetting Cassie-Baxter state.

[23] In some embodiments, the modified surface is above the heat exchanger or heat transfer surface.
[24] In some embodiments, the modified surface is on the surface of glass, windows, mirrors, or lenses.

[25] In some embodiments, the modified surface is patterned on the glass component so that condensation occurs in an aesthetically or functionally desirable manner.
[26] In some embodiments, the modified surface is on a computer case or cooling rack. In some embodiments, the modified surface is on a gas vaporizer, eg, a gas vaporizer heat exchanger. In some embodiments, the modified surface is in the vaporizer device, which prevents or reduces deposits in the form of condensation on the vaporizer device.

[27] In some embodiments, the modified surface is in the engine or combustion nozzle, for example, the modified surface prevents or reduces the condensation of carbon dioxide in the engine or combustion nozzle.

[28] In some embodiments, the modified surface is on top of an industrial gas and / or liquid processing apparatus, for example, the modified surface is an industrial gas and liquid treatment in the processing apparatus. Prevents or reduces the formation of water and gaseous hydrates in and / or clathrate compounds. In one embodiment, the material is raw natural gas and the phase change involves hydration or host-guest complexing (eg, formation of a solid material). In some embodiments, the first phase is a gas (eg, vapor) or liquid and the second phase is a supercritical phase.

[29] In some embodiments, the modified surface is on top of a metal vapor illumination or advanced lithography equipment, for example, the modified surface is of metal vapor illumination or metal vapor in operation of the advanced lithography equipment. Prevents or reduces condensation. In one embodiment, uniformity and deposition prevention are important for the accurate operation of advanced lithography equipment.

[30] In another aspect, as compared herein, it increases the energy barrier to phase change from the first phase to the second phase, or the driving force required for the phase change. A heat exchanger or heat transfer surface that includes the modified surface described is provided, and the occurrence of phase changes in the heat exchanger or heat transfer surface compared to the heat exchanger or heat transfer surface that does not include the modified surface. Prevented or delayed.

[31] In another embodiment, the energy barrier to a phase change from the first phase to the second phase, or the driving force required for the phase change, is increased as compared to the unmodified surface. A glass, window, mirror, or lens containing the modified surface described is provided and is on the glass, window, mirror, or lens as compared to a glass, window, mirror, or lens that does not contain the modified surface. The occurrence of phase changes is prevented or delayed.

[32] In another embodiment, the energy barrier against a phase change from the first phase to the second phase, or the driving force required for the phase change, is increased as compared to the unmodified surface, as described herein. Glass components are provided that include the patterned modified surface described to prevent or delay the occurrence of phase changes on the modified surface as compared to the unmodified surface. For example, patterning can provide a decorative and / or functionally desirable pattern on the glass such that condensation occurs in an aesthetically pleasing and / or functional form.

[33] In another embodiment, as described herein, it increases the energy barrier to phase change from the first phase to the second phase, or the driving force required for the phase change, as compared to an unmodified surface. A computer case or cooling rack containing the modified surface described is provided to prevent or delay the occurrence of phase changes on the computer case or cooling rack compared to a computer case or cooling rack that does not contain the modified surface. NS. For example, the modified surface may prevent or reduce condensation-related damage to electronic equipment or computer equipment contained therein.

[34] In another embodiment, as compared herein, it increases the energy barrier to a phase transition from a first phase to a second phase, or the driving force required for a phase transition. A gas vaporizer with the described modified surface is provided to prevent or delay the occurrence of phase changes on the gas vaporizer as compared to a gas vaporizer without the modified surface. For example, the modified surface may prevent or reduce condensation and / or frost on the inner vaporizer heat exchanger.

[35] FIG. 1A is a diagram showing the phase change of water on surface-modified and unmodified aluminum plates described in Example 1. FIG. 1B is a diagram showing the phase change of water on the surface-modified and unmodified aluminum plates described in Example 1. [36] FIG. 6 is a graph showing the results of ice formation in surface-modified and unmodified heat exchangers in the experiment described in Example 2. [37] FIG. 6 is a schematic diagram showing a closed-loop air conditioning system described in Example 3. [38] FIG. 6 is a graph showing the results of adding a condensed nucleation barrier to the heat exchanger as described in Example 3. [39] FIG. 5A is a diagram showing the temporal progression of the liquid-to-solid phase change of water on unmodified and modified surfaces as described in Example 4. FIG. 5B is a diagram showing the temporal progress of the phase change of water from liquid to solid on the unmodified surface and the modified surface described in Example 4. FIG. 5C is a diagram showing the temporal progress of the phase change of water from liquid to solid on the unmodified surface and the modified surface described in Example 4. FIG. 5D is a diagram showing the temporal progression of the liquid-to-solid phase change of water on the unmodified and modified surfaces described in Example 4. FIG. 5E is a diagram showing the temporal progress of the phase change of water from liquid to solid on the unmodified surface and the modified surface described in Example 4. [40] FIG. 5 is a graph showing a plot of ice thickness vs. time for unmodified and modified surfaces in an environmental chamber with controlled air velocity and surface temperature as described in Example 5. [41] It is a graph which shows the pressure drop on the air side of the reformed heat exchanger and the unmodified heat exchanger described in Example 6.

[42] The ability to condense droplets in a rounded state with high contact angles reduces the effective temperature of condensation below the bulk dew point by increasing the energy barrier of droplet formation. As used herein, a modified surface that prevents or delays the occurrence of condensation or frost formation under certain environmental conditions, such as temperature and / or relative humidity, by increasing the energy barrier to nucleation phase changes. And methods are provided. The materials and methods described herein are applicable to systems where condensation and / or ice formation is not desirable. In addition, methods are provided to increase safety in specific applications or to extend the range of environmental conditions for the safe or effective operation of such systems. Methods for improving performance by delaying or eliminating the need for defrosting or drying of such systems are also provided.

[43] Other phase change phenomena addressed by the materials and methods described herein include _{the formation of solid carbon dioxide from CO 2} systems, such as the formation of clathrate hydrates in deep sea exploration systems. And the condensation of vapor phase compounds in the vaporization system. Systems operating in both subcritical and supercritical operating conditions are also covered.

[44] In some embodiments, a system such as a heat exchanger operates at a lower temperature without causing condensation as compared to the same system that does not include the surface modifications described herein. Or it can handle larger temperature fluctuations. In some embodiments, nucleation can be suppressed by ultracooling below 5 ° C. (difference between dew point and surface temperature).
[45] In some embodiments, the surface modification comprises a nanostructured composition.

Definition
[46] The numerical ranges presented herein include numerical values that define the range.

[47] "One (a)", "one (an)" and "the" include references to the plural unless the context dictates otherwise.
[48] An "equilibrium phase transition value" is a temperature / pressure condition in which a phase change can occur thermodynamically without an energy barrier. This phase change can be a transition at either the dew point (eg, condensation), the frost point (eg, frost), or the freezing point (eg, crystallization), which occurs when the transition phase reaches saturation. .. "Frost point" refers to the formation of a lower density solid aqueous phase, and "freezing point" refers to the formation of near-perfect ice. Typically, in the case of water, the frost looks white and powdery like snow, and the frozen / ice is denser, optically clear ice.

[49] “Uniform nucleation energy” refers _{to the energy barrier ΔG homo} ^* for nucleation, as defined in classical nucleation theory.
[50] A "dew point" is the temperature for a given set of environmental pressure and humidity conditions in which the liquid water phase is energetically more advantageous than the vapor phase. This is where condensation occurs in the absence of energy barriers.

[51] A "contact angle" is the angle measured through the liquid between the surface at the contact surface and the liquid-vapor interface.
[52] "Free surface energy" refers to the energy of an interface (liquid-steam, solid-liquid, or steam-solid). High-energy surfaces get wet more easily than low-energy surfaces.

[53] The "barrier coating" forms a physical barrier, thus minimizing contact with unwanted elements (eg, water (as "moisture barrier"); electrolytes (as "corrosion barrier"). ..

[54] "Chemical coating" refers to a surface layer in which a reactant chemically reacts with the surface to be treated.
[55] “Nanostructure” coating refers to a coating composition characterized by being less than 100 nanometers in at least one dimension.

[56] "Condensation condition" refers to the condition in which the surface is cooled below the dew point of steam.
[57] "Sensible heat" refers to the amount of heat due to a change in the temperature of a gas or object without changing the phase.

[58] "Sensible heat cooling capacity" refers to the amount of heat that can be transferred to a material in the absence of phase change.
[59] "Latent heat" is the energy (eg, heat) required to change a phase without a temperature change (eg, between a solid phase and a liquid or gas phase; or between a liquid and a gas phase). Refers to the amount of.

[60] "Latent heat cooling capacity" refers to the amount of energy (eg, heat) that can be transferred to or from a material by phase change.
[61] "Sensible heat ratio" refers to the ratio of sensible heat cooling capacity to total cooling capacity. The total cooling capacity is often the sum of the sensible heat cooling capacity and the latent heat cooling capacity.

[62] A "cassy-Baxter state" refers to the formation of a state in which a droplet is on a textured surface where a hybrid interface is present, typically of a gaseous phase trapped beneath the surface of the droplet. It is a form.

[63] "Wenzel state" refers to the formation of a state in which a certain amount of liquid is in contact with the textured surface and the liquid is wetting the underlying surface.
[64] "Raw natural gas" refers to untreated natural gas, which includes liquids of natural gas (eg, condensates, natural gas, liquefied petroleum gas), water, and other impurities (eg, nitrogen,). It may contain carbon dioxide, hydrogen sulfide, helium).

[65] As used herein, "hydration" and "host-guest complex formation" associated with phase change refer to the formation of different phases by the uptake of water, or the formation of clathrates or clathrate-like structures.

[66] “Clathrate” refers to a compound in which the molecule of one substance is physically trapped within the crystal structure of another substance.
[67] "Supercritical conditions" refers to the temperature and pressure conditions under which a material is in the supercritical phase. "Supercritical phase" refers to a fluid with a temperature and pressure higher than its critical temperature and pressure. The critical temperature of a substance is the temperature at which the vapor of the substance cannot be liquefied no matter how much pressure is applied above that temperature. The critical pressure of a substance is the pressure required to liquefy a gas at the critical temperature.
[68] "supercool" or "subcool" (supercooling) is the equilibrium phase change temperature (eg, for example) of a substance in the first phase to a second phase under a given pressure. Refers to cooling to a temperature below the dew point or freezing point, and the substance does not transition to the second phase (eg, the substance cools below the dew point without becoming liquid, or the substance is below the freezing point without becoming solid. It gets cold).

Surface modification
[69] As used herein, surface modifications are provided that maintain spherical or substantially spherical droplets with a size below the uniform nucleation critical radius, thereby causing surface temperature at the time of nucleation below the dew point. Is brought. In some embodiments, water does not condense on the modified surface described herein, even if the surface temperature is below the equilibrium dew point (eg, sufficient material agglomerates and is easily observable. Or form a liquid phase large enough to measure the contact angle).

[70] In some embodiments, the surface modification is in the form of a barrier coating, a chemical coating, or a combination thereof. In one embodiment, the surface modification is a nanostructured surface modification. Surface modification results in a reduction in free surface energy, which makes the droplet more spherical with a size less than the critical nucleation radius.

[71] In certain embodiments, the surface modification comprises a metal oxide or polymer. In one embodiment, the surface modification comprises a polymer containing an alkyl or fluoroalkyl monomer unit. In one embodiment, the surface modification comprises a metal oxide layer created by deposition or conversion. In one embodiment, the surface modification is terminated with an alkyl or fluorinated compound (s).

[72] In some non-limiting embodiments, the surface is 0.1M-2M with a Group II or transition metal salt such as, for example, 0.25M-1M zinc nitrate, magnesium nitrate, and / or manganese sulfate. By immersing the washed substrate in a mixture of amines such as hexamine or urea at a solution temperature of about 40 ° C to about 90 ° C for about 5 minutes to about 2 hours, with a nanostructured mixed metal oxide. It is reformed. The sample can then be removed from the solution, rinsed and baked at a temperature of about 100 ° C to about 600 ° C. The sample is then placed in a dilute solution of the hydrophobic chemical, eg, a hexane solution of stearate, an isopropanol solution of hexadecylphosphonic acid, or a solution containing perfluorodecyltriethoxysilane in ethanol for about 5 minutes to about. It can be immersed for 120 minutes. The substrate can then be removed and dried in an oven at about 105 ° C. for about 1 hour.
[73] Non-limiting embodiments of surface modifications that may be used herein are described, for example, in WO 2018/053452 and WO 2018/053453, which are incorporated herein by reference in their entirety.

Use applications
[74] In the use of modified surfaces described herein, the surface increases the energy barrier to phase change from the first phase to the second phase.

[75] In some embodiments, the first phase is subcooled below the equilibrium phase transition value to the second phase and is still present as the first phase. For example, the first phase is about 0.25 ° C. to about 10 ° C., about 0.25 ° C. to about 1 ° C., about 0.5 ° C. to about 2 ° C., from the equilibrium phase transition value to the second phase. It may be subcooled to a temperature below 1 ° C. to about 5 ° C., about 3 ° C. to about 5 ° C., or about 5 ° C. to about 10 ° C. and still present as the first phase. In some embodiments, the first phase is about 0.25 ° C, 0.5 ° C, 1 ° C, 2 ° C, 3 ° C, 4 ° C, 5 ° C, from the equilibrium phase transition value to the second phase. It may be subcooled to a temperature greater than any of 6 ° C, 7 ° C, 8 ° C, 9 ° C, or 10 ° C and still present as the first phase.

[76] In some embodiments, the energy barrier to the phase change from the first phase to the second phase is about 50% to about 99%, about 50% to about 70%, about 70% of the uniform nucleation energy. 60% to about 80%, about 70% to about 90%, about 80% to about 90%, about 85% to about 95%, or about 95% to about 99%. In some embodiments, the energy barrier may be greater than any of about 50%, 60%, 70%, 80%, 90%, 95%, or 99% of the uniform nucleation barrier.

[77] In some embodiments, nucleation is suppressed by supercooling above about 5 ° C.
[78] In one embodiment, the first phase consists of water vapor or is essentially water vapor, and the second phase is water liquid or ice. In another embodiment, the first phase is water vapor containing air and the second phase is liquid water or ice. In another embodiment, the first phase is liquid water and the second phase is water ice. In another embodiment, the first phase consists of air and water vapor, or essentially consists of air and water vapor, and the second phase is water ice. In another embodiment, the first phase is carbon dioxide vapor and the second phase is carbon dioxide ice (dry ice). In another embodiment, the first phase is a liquid and the second phase is a condensation of a solid phase. In another embodiment, the first phase is metal vapor and the second phase is condensed metal vapor.

[79] In some embodiments of the applications described herein, condensed droplets at the critical radius of formation are present on the modified surface in a dewetting state (ie, Cassie Baxter state). ..
[80] The use of heat exchangers / heat transfer involves using the materials herein to facilitate heat exchange and reduce the temperature at which condensation is observed. In addition, using these materials on heat exchangers to reduce the temperature at which frost occurs increases operational execution time, minimizes the impact of ice formation on heat transfer performance, and of the system. By increasing the operating range, it benefits more than conventional materials. Heat exchangers are also provided in which the materials described herein are included, for example, as a coating or layer on one or more surfaces of the heat exchanger, the surface materials facilitate heat exchange and condensation is observed. It provides the functional property of lowering the temperature and / or the temperature at which frost occurs.

[81] Applications for glass windows, mirrors, or lenses include the use of surface modifications described herein to prevent condensation that is undesirable for visual applications. In addition, the usage is a water, wine or beer glass so that condensation occurs in a material that can be patterned and used to provide a decorative pattern on the glass, eg, in an aesthetically pleasing manner. It may include forming a pattern on the outside of the. Glasses, mirrors, and lenses that include, for example, as a coating or layer, the materials described herein on the surface of glass, mirrors, or lenses are also provided, and the surface materials are functional in that they prevent unwanted condensation. It provides properties and, in some embodiments, includes a surface coating or layer of a decorative pattern.

[82] Applications for computer case / rack cooling include using the surface modifications described herein to prevent damage to electronics associated with unwanted condensation. Further, the method of use also includes applying the surface modifications described herein to provide an additional operational barrier to the formation of condensates on the coldest components of a computer case or rack. good. Increasing the propulsion required for condensation provides additional safety operational margin. Computer cases and / or racks that include, for example, as a coating or layer, the surface modifications described herein on the surface of a computer case or rack are also provided, and the surface material can damage the electronics. It provides the functional property of preventing certain unwanted condensations.

[83] Gas vaporizers are used for undesired condensation on vaporizer heat exchangers, such as, but not limited to, liquid nitrogen exchangers using the surface modifications described herein. Includes preventing frost. The formation of condensates and ice on the vaporizer heat exchanger reduces the available flow of expanded gas or requires a larger heat exchanger to limit the effectiveness of the heat exchanger. A secondary advantage of the use of surface modifications described herein is an increased ability to shed ice formed on the exchanger. Also provided are gas vaporizers comprising surface modifications described herein, eg, as coatings or layers, on the surface of gas vaporizers, eg, on the surface of vaporizer heat exchangers such as liquid nitrogen exchangers. The surface material provides the functional property of preventing unwanted condensation and / or frost.

[84] Applications of antifouling condensation include using the surface modifications described herein to prevent unwanted condensation on the vaporizer device. In these embodiments, prevention of condensation is intended to prevent the adhesion and deposition of heavier components and natural oils. One example is a glycol-based e-cigarette or other similar device. Additional antifouling applications include nozzle-based thermal printers and devices. Vaporizers comprising surface modifications described herein, eg, as coatings or layers, are also provided on the surface of vaporizers such as e-cigarettes or similar devices, or thermal printers or device nozzles, surface materials. Provides the functional properties of preventing condensation and the adhesion and / or deposition of heavy components and oils.

[85] Applications for engine / nozzle icing include preventing the condensation of carbon dioxide in engine and combustion nozzle applications. Combustion engines and nozzles are also provided on the surface of the engine or nozzle, including, for example, the surface modifications described herein as a coating or layer, the surface material having the functional property of preventing the condensation of carbon dioxide. offer.

[86] Hydrate and inclusion compound prevention uses include water and gas during the treatment of industrial gases and liquids in treatment equipment, such as compressed natural gas production or methane inclusion compound deposition in high pressure drilling applications. Includes preventing the formation of hydrates. Industrial gas and liquid treatments, including, for example, surface modifications described herein as coatings or layers, are also provided on the surface of the treatment equipment, where the surface material is water and gas hydrate formation. Provides the functional property of preventing.

[87] Applications for metal vapor condensation prevention include preventing metal vapor condensation during operation for metal vapor lighting, or advanced lithography applications, where uniformity and deposition prevention are important for accurate operation. Metal vapor illumination and lithography equipment is also provided on the surface of the equipment, including, for example, surface modifications described herein as coatings or layers, the surface material having the ability to prevent metal condensation during operation of the equipment. Provides a characteristic.

[88] The following examples are intended to illustrate the invention, but are not intended to limit the invention.

Example 1
[89] 40 ° C.-90 in a mixture of Group II or transition metal salts such as 0.25M-1M zinc nitrate, magnesium nitrate and / or manganese sulfate and amines such as 0.1M-2M hexamine or urea. The aluminum plate was modified with a nanostructured mixed metal oxide by immersing the washed aluminum plate at a solution temperature of ° C. for a period of 5 minutes to 2 hours. The sample was then removed from the solution, rinsed and baked at a temperature of 100 ° C. to 600 ° C. The sample was then immersed in a hexane dilute solution of stearic acid, a hexadecylphosphonic acid dilute solution of isopropanol, or a solution containing perfluorodecyltriethoxysilane in ethanol for 30-90 minutes. The sample was then removed and dried in an oven at 105 ° C. for 1 hour.

[90] A surface-modified aluminum plate was placed on the surface and photographed through a microscope while being cooled to −10 ° C. Condensation was observed to begin much earlier in the uncoated sample, much slower in the coated sample, and condensation began when the surface temperature was lowered below the dew point (FIG. 1A). Continuing the experiment, the uncoated sample nucleated water into ice, while the coated sample remained liquid water (Fig. 1B). This example shows a nucleation barrier for both vapor-to-liquid and liquid-to-solid transitions.

Example 2
[91] The surface of the heat exchanger was modified with a nucleation barrier coating as described in Example 1. An icing test was carried out to determine the occurrence of frost by simultaneously cooling the heat exchanger and air to a temperature below 0 ° C. in a closed loop wind tunnel. Figure 2 shows the results of the test, where the unmodified heat exchanger began to form ice and the surface modified heat exchanger did not form ice (labeled central band, nucleation barrier). ). This surface modification lowered the temperature of nucleation by about 2 ° C. as compared to the unmodified surface of the control.

Example 3
[92] As shown in FIG. 3, a closed-loop air conditioning system circulates indoor air at 30 ° C. and 50% relative humidity (RH) through a server rack, where the air is heated to about 40 ° C. and 27% RH. NS. The air is immediately passed through a liquid air heat exchanger in which the coolant enters at 20 ° C.

[93] As shown in FIG. 4, both air entering and exiting the server rack has an equilibrium dew point of 18 ° C. The use of unmodified heat exchangers leaves a 2 ° C error in the control system to prevent condensation that can drip into the server rack. By adding a condensed nucleation barrier to the heat exchanger, an energy barrier is added, condensation is not observed up to 16 ° C, effectively doubling the safety margin and adding additional protection to the device.

Example 4
[94] Two 3003 aluminum plates, one modified and one unmodified control, were placed side by side on a cooling plate cooled to −10 ° C. and thermally coupled. The air temperature was about 22 ° C. and the humidity was 40%. This air was passed through a 243.84 cm (8 ft) long wind tunnel at a frontal wind speed of approximately 2 m / s and through the surfaces of these plates. The surface was modified in the same procedure as in Example 1. Before starting this experiment, the cooling plate was turned on and off, the cooling plate was frosted for 1 hour, and defrosted for 10 minutes. The progression of the images in FIGS. 5A-5E shows the phase change over time from the time point of about 30 seconds in FIG. 5A to the time point of about 1 hour in FIG. 5E. The modified surface delays the phase transition from liquid water to water ice and slows its subsequent formation. After 1 hour, liquid water is still present on the modified sample, but in the unmodified sample the liquid water freezes completely.

Example 5
[95] The unmodified aluminum plate and the aluminum plate modified according to the method described in Example 1 were placed on a thermoelectric cooling plate set to a surface temperature of about −5 ° C. In the wind tunnel, the front wind speed was 1.5 m / s, the air temperature and relative humidity were 25 ° C. and 40%, respectively, and air was passed across the plate. Ice thickness was measured using a microscope and the cross section was considered a function of time. A plot of ice thickness as a function of time is illustrated in FIG. On the modified aluminum plate, microscopic measurements began with frost formation starting at 11 minutes and taking 6 minutes longer to form frost than the unmodified plate. This barrier delay in phase change continued throughout the duration, resulting in a 3 mm thin layer of ice after 2 hours. The thickness of ice on the unmodified plate was 7 mm, whereas the thickness of ice on the modified plate was 4 mm.

Example 6
[96] Aluminum fin stainless steel pipe heat exchangers with four parallel fins per 2.54 cm (1 inch) were modified with a phase change barrier coating as described in Example 1. Tested in a wind tunnel compared to an unmodified heat exchanger. The temperature of the glycol refrigerant was set to -4 ° C and passed through the tube side of the coil at a flow rate of about 800 grams per second. Air was passed through the fin side of the coil at a front wind speed of 3 m / s and inlet temperature and humidity of 2 ° C. and 83%, respectively. The heat transfer capacity of the coil and the pressure drop on the air side were monitored for 5 hours. On the unmodified coil, water condensed from the air and immediately frozen on a surface that was below the freezing point of the water. This increased the pressure drop. On heat exchangers where the fins have been modified with a phase change barrier coating, the liquid water on the surface takes a much longer time to freeze, resulting in the water condensed from the air flowing out of the coil for an extended period of time. bottom. After 5 hours, the air pressure drop on the unmodified coil was about 195 Pa and the air pressure drop on the modified coil was about 140 Pa. This delay in the liquid-to-solid phase change resulted in an improvement of about 30% in the air pressure drop. A plot of air pressure drop as a function of time is shown in FIG.

[97] The invention described above has been described in some detail as examples and examples to clarify understanding, but deviates from the spirit and scope of the invention described in the appended claims. It is clear to those skilled in the art that certain changes and modifications can be made without. Therefore, the description should not be construed as limiting the scope of the invention.

[98] All publications, patents, and patent applications cited herein specifically and individually indicate that an individual publication, patent, or patent application is incorporated by reference for any purpose. The whole is incorporated herein by reference in its entirety, as if it had been.

Claims (57)

A method for preventing or delaying the occurrence of phase changes on the surface.
In the step of providing a modified surface including surface modification, the modified surface is compared with an unmodified surface which is the same as the modified surface except that the modified surface does not contain the surface modification. For substances in contact with the quality surface, the steps that increase the energy barrier to the phase change from the first phase to the second phase, or the driving force required for the phase change; and the vapor phase and / or liquid. A step of bringing a fluid stream containing at least one first phase substance containing a phase substance into contact with the modified surface under environmental conditions where a phase change to the second phase can occur on the unmodified surface. ;
Including
The method, wherein the phase change is prevented or delayed on the modified surface as compared to the unmodified surface. The at least one first phase comprises a vapor phase, the second phase comprises a liquid phase, and the prevention or delay of the phase change prevents the condensation of the vapor forming the liquid on the surface. Or the method of claim 1, comprising delay. The method of claim 2, wherein the vapor is water vapor, the fluid flow is air, and the prevention or delay of the phase change comprises preventing or delaying the condensation of the water vapor on the surface. The at least one first phase comprises a steam phase, the second phase comprises a solid phase, and the steam condenses on the surface to form a condensate, preventing or delaying the phase change. The method of claim 1, comprising preventing or delaying the solidification of the condensate forming a solid on the surface. The vapor is water vapor, the fluid stream is air, the condensate is a water condensate, and the prevention or delay of the phase change is the water condensate forming frost or ice on the surface. 4. The method of claim 4, comprising preventing or delaying the coagulation of ice cubes. The at least one first phase comprises a vapor phase and a liquid phase, the second phase comprises a liquid phase, and the prevention or delay of the phase change is such that the vapor forming the liquid on the surface. The method of claim 1, comprising preventing or delaying condensation. 6 The method described. The at least one first phase comprises a vapor phase and a liquid phase, the second phase comprises a solid phase, and the surface comprises a condensate from the steam and / or liquid to prevent or prevent the phase change. The method of claim 1, wherein the delay comprises preventing or delaying the solidification of the condensate and / or the liquid forming a solid on the surface. The steam is water vapor, the liquid is water, the fluid stream is air, the surface contains a condensate of water vapor and / or liquid water, and the prevention or delay of the phase change is on the surface. 8. The method of claim 8, comprising preventing or delaying the coagulation of the water condensate and / or liquid water on the surface forming frost or ice. The at least one first phase comprises a vapor phase, the second phase comprises a solid phase, and the prevention or delay of the phase change prevents solidification of the vapor forming the solid on the surface. Or the method of claim 1, comprising delay. The steam is water vapor, the solid is water frost or ice, and the prevention or delay of the phase change comprises preventing or delaying the solidification of the water vapor forming the water frost or ice on the surface. The method according to claim 10. The vapor is a CO ₂ gas, the solid is frozen CO ₂ , and the prevention or delay of the phase change prevents or delays the solidification of the _{CO 2 gas forming the frozen CO 2} on the surface. The method of claim 10, comprising delay. The method of claim 1, wherein the modified surface is supercooled below the equilibrium phase transition value from the first phase to the second phase and the material is still present in the first phase. The modified surface is supercooled to a temperature greater than about 0.25 ° C. below the equilibrium phase transition value from the first phase to the second phase, and the material is still present in the first phase. The method according to claim 13. The modified surface is supercooled to a temperature greater than about 0.5 ° C. below the equilibrium phase transition value from the first phase to the second phase, and the material is still present in the first phase. The method according to claim 14. Claim that the modified surface is supercooled to a temperature more than about 1 ° C. below the equilibrium phase transition value from the first phase to the second phase and the material is still present in the first phase. 15. The method according to 15. Claim that the modified surface is supercooled to a temperature greater than about 2 ° C. below the equilibrium phase transition value from the first phase to the second phase and the material is still present in the first phase. 16. The method according to 16. Claim that the modified surface is supercooled to a temperature greater than about 3 ° C. below the equilibrium phase transition value from the first phase to the second phase and the material is still present in the first phase. 17. The method according to 17. Claim that the modified surface is supercooled to a temperature greater than about 5 ° C. below the equilibrium phase transition value from the first phase to the second phase and the material is still present in the first phase. 18. The method according to 18. Claim that the modified surface is supercooled to a temperature greater than about 10 ° C. below the equilibrium phase transition value from the first phase to the second phase and the material is still present in the first phase. 19. The method according to 19. The method of claim 1, wherein the energy barrier to the phase change from the first phase to the second phase is greater than about 50% of the uniform nucleation energy. 21. The method of claim 21, wherein the energy barrier to the phase change from the first phase to the second phase on the modified surface is greater than about 60% of the uniform nucleation energy. 22. The method of claim 22, wherein the energy barrier to the phase change from the first phase to the second phase on the modified surface is greater than about 70% of the uniform nucleation energy. 23. The method of claim 23, wherein the energy barrier to the phase change from the first phase to the second phase on the modified surface is greater than about 80% of the uniform nucleation energy. 24. The method of claim 24, wherein the energy barrier to the phase change from the first phase to the second phase on the modified surface is greater than about 90% of the uniform nucleation energy. 25. The method of claim 25, wherein the energy barrier to the phase change from the first phase to the second phase on the modified surface is greater than about 95% of the uniform nucleation energy. 26. The method of claim 26, wherein the energy barrier to the phase change from the first phase to the second phase on the modified surface is greater than about 99% of the uniform nucleation energy. The phase change from the first phase to the second phase involves nucleation of the material on the surface modification, and the surface modification comprises a barrier coating, a chemical coating, or a combination thereof. The method according to any one of claims 1 to 27, including the method according to any one of claims 1 to 27. 28. The method of claim 28, wherein the surface modification in which nucleation occurs is nanostructured. 28 or 29. The method of claim 28 or 29, wherein the surface modification in which nucleation occurs comprises a metal oxide or polymer. 30. The method of claim 30, wherein the surface modification in which nucleation occurs comprises a polymer comprising an alkyl or fluoroalkyl monomer unit. 30. The method of claim 30, wherein the surface modification in which nucleation occurs comprises a metal oxide layer created by deposition or conversion. The method of any of claims 30-32, wherein the surface modification in which nucleation occurs comprises one or more terminal alkyl or fluorinated compounds. The method according to claim 1, wherein the substance is water, the first phase mainly contains water vapor, and the second phase contains liquid water or water ice. The method of claim 1, wherein the substance is water, the first phase contains water vapor in the air, and the second phase is liquid water or water ice. The method of claim 1, wherein the substance is water, the first phase is liquid water, and the second phase is water ice. The method of claim 1, wherein the substance is carbon dioxide, the first phase contains carbon dioxide vapor, and the second phase is dry ice. The method of claim 1, wherein the substance is raw natural gas, the first phase contains gaseous vapors, and the second phase contains clathrate compounds. The method of claim 1 or 38, wherein the first phase is vapor or liquid and the second phase is a supercritical phase. The method according to claim 1, wherein the substance is a metal, the first phase contains metal vapor, and the second phase contains condensed metal vapor. A heat exchanger or heat transfer surface that includes a modified surface that includes surface modification and is compared to an unmodified surface that is identical to the modified surface except that the modified surface does not contain the surface modification. Then, for the substance in contact with the modified surface, the energy barrier against the phase change from the first phase to the second phase, or the propulsive force required for the phase change is increased. The heat exchanger or heat transfer surface that prevents or delays the occurrence of the phase change in the heat exchanger or heat transfer surface as compared to a heat exchanger or heat transfer surface that does not include a quality surface. The method of claim 1, wherein the modified surface is above a heat exchanger or heat transfer surface. A glass, window, mirror, or lens that includes a modified surface that includes a surface modification and that is the same unmodified surface as the modified surface except that the modified surface does not contain the surface modification. In comparison, the substance in contact with the modified surface increases the energy barrier against the phase change from the first phase to the second phase, or the propulsive force required for the phase change. The glass, window, mirror, which does not contain a modified surface, prevents or delays the occurrence of the phase change on the glass, window, mirror, or lens as compared to the glass, window, mirror, or lens. Or a lens. The method of claim 1, wherein the modified surface is on the surface of glass, a window, a mirror, or a lens. A glass component that includes a patterned modified surface that includes surface modifications and is compared to an unmodified surface that is identical to the modified surface except that the modified surface does not contain the surface modification. Then, for the substance in contact with the modified surface, the energy barrier against the phase change from the first phase to the second phase, or the propulsive force required for the phase change is increased, and the above-mentioned non-phase change is performed. The occurrence of the phase change on the modified surface is prevented or delayed as compared to the modified surface, and the modified surface is decorated on the glass so that the phase change occurs in an aesthetically pleasing manner. The glass component, which is configured in a similar pattern. The method of claim 1, wherein the modified surface is patterned on a glass component so that the phase change occurs in an aesthetically pleasing manner. A computer case or cooling rack that includes a modified surface that includes surface modification compared to an unmodified surface that is identical to the modified surface except that the modified surface does not contain the surface modification. The substance in contact with the modified surface increases the energy barrier against the phase change from the first phase to the second phase, or the propulsive force required for the phase change, and the modified surface. The occurrence of the phase change on the computer case or cooling rack is prevented or delayed, the phase change involves condensation of water, and the modified surface is not. The computer case or cooling rack that prevents or reduces condensation-related damage to the electronic equipment contained therein as compared to the modified surface. The method of claim 1, wherein the modified surface is on a computer case or cooling rack. A gas vaporizer or gas vaporizer heat exchanger containing a modified surface including surface modification, which is the same unmodified surface as the modified surface except that the modified surface does not contain the surface modification. Compared to the surface, the substance increases the energy barrier against the phase change from the first phase to the second phase, or the propulsive force required for the phase change, said on the gas vaporizer. The occurrence of a phase change is prevented or delayed, the substance is water, the phase change involves condensation of water and / or formation of frost, and the modified surface is the gas as compared to an unmodified surface. The gas vaporizer or gas vaporizer heat exchanger that prevents or reduces condensation and / or frost formation in the vaporizer or gas vaporizer heat exchanger. The method of claim 1, wherein the modified surface is above a gas vaporizer. The method of claim 50, wherein the modified surface is above a gas vaporizer heat exchanger. The modified surface is in the vaporizer device, the substance is water, the phase change involves condensation of water, and the modified surface is on the vaporizer device as compared to an unmodified surface. The method of claim 1, wherein the deposits in the form of condensation in the water are prevented or reduced. The modified surface is in an engine or combustion nozzle, the substance is carbon dioxide, the phase change involves condensation of carbon dioxide, and the modified surface is the engine as compared to an unmodified surface. Alternatively, the method of claim 1, wherein the condensation of carbon dioxide in the combustion nozzle is prevented or reduced. The modified surface is on a processing apparatus for industrial gases and / or liquids, the material is raw natural gas, the phase change comprises hydration or host-guest complex formation, said modified. A claim that the surface prevents or reduces the formation of water and gas hydrates and / or inclusion compounds during the treatment of the industrial gases and liquids in the treatment apparatus as compared to an unmodified surface. The method according to 1. 54. The method of claim 54, wherein the first phase is vapor or liquid and the second phase is a supercritical phase. The modified surface is on a metal vapor illumination or advanced lithography equipment, the material is metal, the phase change involves condensation of metal vapor, and the modified surface is the metal vapor illumination or advanced lithography. The method of claim 1, wherein the method of preventing or reducing the condensation of metal vapors during operation of the device. 56. The method of claim 56, wherein uniformity and prevention of deposition are important for the accurate operation of the advanced lithography apparatus.

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